#include <stdio.h>
#include <unistd.h>

int global_value = 100;

int main()
{
   pid_t id=fork();
   if(id <0)
    {
        printf("fork error\n");
        return 1;
    }
    else if(id == 0)
    {
        int cnt=0;
       // printf("child\n");
       while(1)
       {
           printf("我是子进程,pid: %d, ppid: %d | global_value : %d, &global_value : %p \n",getpid(),getppid(), global_value,&global_value);
           sleep(1);
           cnt++;
           if(cnt==10)
           {
               global_value=300;
               printf("子程序已经更改了全局的变量了............\n");
           }
       }
    }
   else
    {
       // printf("father\n");
       while(1)
       {
           printf("我是父进程,pid: %d, ppid: %d | global_value : %d, &global_value : %p \n",getpid(),getppid(), global_value,&global_value);
           sleep(2);
       }
    }
    sleep(1);
    return 0;
}
